#include<bits/stdc++.h>
using namespace std;

#define int long long

typedef long long ll;
typedef pair<int,int>pint;
typedef vector<int>vint;
typedef vector<pint>vpint;
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define all(v) (v).begin(),(v).end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define reps(i,f,n) for(int i=(f);i<(n);i++)
#define each(it,v) for(__typeof((v).begin()) it=(v).begin();it!=(v).end();it++)
template<class T,class U>void chmin(T &t,U f){if(t>f)t=f;}
template<class T,class U>void chmax(T &t,U f){if(t<f)t=f;}

int N;
char A[114][514];
vpint v;


char B[114][514];
int cnt[114];
int f(int b){
    rep(i,N)rep(j,N)B[i][j]=A[i][j];
    rep(i,v.size()){
        B[v[i].fi][v[i].se]='o';
        B[v[i].se][v[i].fi]='x';
        if(b>>i&1)swap(B[v[i].fi][v[i].se],B[v[i].se][v[i].fi]);
    }

    memset(cnt,0,sizeof(cnt));
    rep(i,N)rep(j,N){
        if(B[i][j]=='o')cnt[i]++;
    }

    vpint u;
    rep(i,N)u.pb(pint(cnt[i],i));
    sort(all(u));reverse(all(u));
    int r=1;
    rep(i,N){
        if(i&&u[i-1].fi!=u[i].fi)r++;
        if(u[i].se==0)return r;
    }
}

signed main(){
    cin>>N;
    rep(i,N)cin>>A[i];
    rep(i,N)rep(j,N){
        if(A[i][j]=='o')A[j][i]='x';
        if(A[i][j]=='x')A[j][i]='o';
    }
    rep(i,N)reps(j,i+1,N)if(A[i][j]=='-')v.pb(pint(i,j));

    int mi=1145141919;
    for(int i=0;i<(1<<v.size());i++){
        chmin(mi,f(i));
    }
    cout<<mi<<endl;
    return 0;
}